1. Field of the Invention
The invention relates a conducting assembly, more particularly to a conducting assembly for a micro switch.
2. Description of the Related Art
FIG. 1 shows a conventional micro switch 10 which is installed in a telephone base (not shown) so as to serve as a plunger of the telephone base and which is depressed by a telephone hand set (not shown) when the telephone set (not shown) is not in use. As best illustrated, the conventional micro switch includes a seat member 1, a pair of conducting assemblies 2, a pivot frame 3, a cover member 4 and a compression spring 5.
The seat member 1 is a rectangular casing with an open top and includes a front wall 111, a rear wall 112 and two opposed side walls 113 which interconnect the front and rear walls 111, 112 to define the casing. A pair of opposed curved notches 11 are formed respectively at the top portion of the opposed side walls 113 adjacent to the front wall 111. A partition 114 divides the casing into a front compartment and a rear compartment in cooperation with the front wall 111 and the rear wall 112. The partition 114 has two engaging grooves 12 in communication with the front compartment. The bottom of the front compartment has four engaging recesses 13 formed therein and aligned with the engaging grooves 12. A pair of conducting plates 14 extend upwardly from the bottom of the rear compartment adjacent to the rear wall 112. Each of the conducting plates 14 has a first end which passes through the bottom of the casing so as to contact respective ones of the electrical circuits of the telephone set. The second end of each of the conducting plates 14 has an upper contact 14' and a lower contact 14" that are located above the bottom so as to be disposed in the rear compartment of the casing. The conducting plates 14 are aligned respectively with the engaging grooves 12 of the partition 114. The rear wall 112 has an engaging projection 15 formed on an inner face thereof.
Each of the conducting assemblies 2 includes an insulating member 23 which encloses partially two conducting units 21. Each of the conducting units 21 includes two leg portions 201a, 202a which are engaged within the engaging recesses 13 of the casing when the insulating member 23 is inserted so as to engage the engaging grooves 12 of the partition 114. The head portions 201', 202' of the conducting units 21 extend out of the insulating member 23 and are substantially perpendicular to the leg portions 201a, 202a. Under this condition, the head portions 201', 202' respectively contact the upper and lower contacts 14', 14" of the respective conducting plate 14.
The pivot frame 3 is made of an insulating material and is provided on the seat member 1. The pivot frame 3 includes a pivot rod 32 which is received by the curved notches 11 of the opposed walls 113, an engaging groove 342 which is formed on an external face of a rear end 34 of the frame 3 and which engages the projection 15 slidingly, and two insulating tabs 341 that are formed on an internal face of the rear end of the frame 3. The insulating tabs 341 are respectively aligned with two contact points respectively constituted by the two head portions 201', 202' and the contacts 14', 14" of the conducting plates 14. A spring retaining unit 33 is formed at an intermediate portion of the pivot frame 3.
The cover member 4 includes a spring retaining unit 41 which projects downwardly therefrom. The cover member 4 is provided on the seat member 1 so as to enclose the pivot frame 3 between the cover member 4 and the seat member 1 with the compression spring 5 being retained by the retaining units 33, 41. When the telephone hand set is on the telephone base, the plunger 31 is depressed downward so as to compress the compression spring 5, wherein the pivot frame 3 pivots counterclockwise about the pivot rod 32 so as to raise the rear end 34 of the pivot frame 3 to dispose the insulating tabs 341 between the head portions 201' of the conducting units 21 and the upper contact 14' of the conducting plates 14, thereby permitting electrical connection between the lower contact 14" and the remaining one of the head portion 202'.
When the telephone hand set is lifted from the base, the plunger 31 of the pivot frame 3 pops up from the telephone base due to the expanding force of the compression spring 5, thereby switching the electrical connection to the position between the upper contact 14' and the head portion 201'.
Referring to FIG. 2, each of the leg portions 201a, 202a of the conducting unit 21 has two opposed faces and a longitudinal rib 22 formed as a reinforcing member along a length thereof with a convex face which is integral with one of the opposed faces and a concave face which corresponds to the convex face and which is integral with the other one of the opposed faces. The insulating member 23 is formed by means of injection molding so as to enclose the intermediate portion of the conducting unit 21. During the formation of the insulating member 23, the mold for receiving the molding substance therein so as to form the insulating member 23 does not enclose any portion of the longitudinal rib 22. If the mold encloses a portion of the longitudinal rib 22, the molding substance will leak via the concave face and the gap between the convex face and the face of the mold. Under such a condition, a part of the leg portions 201a, 202b will have some barrier formed by the molding substance which makes it difficult to insert of the leg portions 201a, 202b through the engaging recesses 13 and to perform the succeeding operations. Thus, the leg portions 201a, 202a of the conducting units 21 are susceptible to break adjacent to the insulating members 23.